A rebate is nothing more than a sales promotion that is used by marketers. It's purpose is to entice customers to buy certain products.
The most-used rebate is a mail-in rebate. This offer requires the buyer to mail in a coupon, their receipt and certain barcodes to receive a check for a specified amount. It usually has a time requirement to send all of these things in and it usually takes 8 to 10 weeks to get the check.
Rebates were originally created by manufacturers to encourage sales by giving some of the retailer's money back to the customers. Rebates are now offered by both manufacturers and retailers. Large stores often work together with the manufactures to offer two or more rebates on a single item. Rebate forms and special receipts are now usually printed by the cash register on a separate receipt.
Rebates are heavily used for advertised sales in retail stores in such as Best Buy and Staples. However, Best Buy, in their April 2004 Earning Call with investors, announced that they would be eliminating most mail-in-rebates as part of their "customer centric" operating shift. Most customers get frustrated when they see a price and find out they have to go through the mail-in rebate process to get that price.
Although rebates are common in the United States and Canada, many areas of the world do not use them, or even consider them to be illegally deceptive under various laws amounting to "Price displayed is price paid".